阅读说明：本技术 一种管束干燥过程中余热利用方法及其应用 (Method for utilizing waste heat in tube bundle drying process and application thereof ) 是由 王峰 刘海涛 刘化丹 赵国盛 吕宝龙 于 2019-10-09 设计创作，主要内容包括：本发明实施例公开了一种管束干燥过程中余热利用方法及其应用,所述利用方法包括管束干燥机干燥过程中排出的废蒸汽和/或冷凝水中余热的回收利用,其中：所述废蒸汽中余热的回收利用包括：将管束干燥机出料口排出的废蒸汽通过一级洗涤塔进行洗涤,用于去除废蒸汽中的有机和/或无机物料,然后,将一级洗涤后的废汽再经过二级碱洗塔洗涤去除其中酸性气体,而一级洗涤后的洗涤液进行闪蒸,再将闪蒸得到的闪蒸汽和二级碱洗后的不饱和蒸汽通过蒸发器加热室对物料进行加热浓缩；上述利用方法能够充分回收利用完管束干燥机中排出的干燥物料后的蒸汽以及冷凝水中的热量,此外,通过三级闪蒸能够最大限度的实现热量的回收利用。(The embodiment of the invention discloses a method for utilizing waste heat in a tube bundle drying process and application thereof, wherein the utilization method comprises the step of recycling waste steam and/or waste heat in condensed water discharged in the tube bundle drying process, wherein the waste steam and/or the waste heat in the condensed water are/is recycled, and the method comprises the following steps: the recycling of waste heat in the waste steam comprises: washing waste steam discharged from a discharge port of the tube bundle dryer by a primary washing tower to remove organic and/or inorganic materials in the waste steam, washing the waste steam subjected to primary washing by a secondary alkaline washing tower to remove acid gas in the waste steam, carrying out flash evaporation on washing liquid subjected to primary washing, and heating and concentrating materials by flash evaporation steam obtained by flash evaporation and unsaturated steam subjected to secondary alkaline washing by an evaporator heating chamber; the utilization method can fully recover and utilize the heat in the steam and the condensed water after the dried materials discharged from the tube bundle dryer are used up, and in addition, the heat can be recovered and utilized to the maximum extent through three-stage flash evaporation.)

1. A method for utilizing waste heat in a tube bundle drying process is characterized by comprising the recycling of waste heat in waste steam and/or condensed water discharged in the drying process of a tube bundle dryer, wherein:

the recycling of waste heat in the waste steam comprises:

washing waste steam discharged from a discharge port of the tube bundle dryer by a primary washing tower to remove organic and/or inorganic materials in the waste steam, washing the waste steam subjected to primary washing by a secondary alkaline washing tower to remove acid gas in the waste steam, carrying out flash evaporation on washing liquid subjected to primary washing, and heating and concentrating materials by flash evaporation steam obtained by flash evaporation and unsaturated steam subjected to secondary alkaline washing by an evaporator heating chamber;

the recycling of waste heat in the condensate water comprises:

and carrying out three-stage series flash evaporation on the condensate water discharged from the tube bundle dryer, heating and concentrating the material by flash steam obtained by the three-stage series flash evaporation through an evaporator heating chamber, and recycling the flash condensate water back to the electric boiler.

2. The utilization method according to claim 1, wherein the recycling of the waste heat in the exhaust steam further comprises:

adjusting the pH value of flash evaporation liquid obtained after flash evaporation to 6.5-8.0, then, feeding the flash evaporation liquid into an IC high-efficiency anaerobic reactor for treatment, heating methane gas generated by treatment by a hot blast stove, adjusting the pH value of treated overflow water to 7.0-8.0, then, sequentially feeding the overflow water into an aerobic treatment tank, a sedimentation tank and an aeration biological filter tank, and discharging the overflow water after reaching the standard.

3. The utilization method of claim 1, wherein in the recovery and utilization of the waste heat in the waste steam, the steam inlet pressure of the primary washing tower and the steam inlet pressure of the secondary alkaline washing tower are respectively 0.2-0.4Mpa, and the temperature of the unsaturated steam after the secondary alkaline washing is 75-90 ℃.

4. The utilization method according to claim 1, wherein the recycling of the waste heat in the exhaust steam further comprises:

and (3) carrying out flash evaporation on the alkaline washing liquid subjected to the secondary alkaline washing, obtaining flash evaporation liquid by flash evaporation and recycling the flash evaporation liquid for the secondary alkaline washing, and heating and concentrating the materials by flash evaporation steam obtained by flash evaporation through an evaporator heating chamber.

5. The utilization method according to claim 1, wherein in the recovery and utilization of the waste heat in the waste steam, the flash evaporation steam inlet pressure is 0.2-0.4Mpa, and the steam outlet pressure is-0.08-0.1 Mpa; the pH value of alkaline liquor used for secondary alkaline washing is 8.0-9.0.

6. The utilization method of claim 1, wherein in the recovery and utilization of the waste heat in the condensed water, the steam inlet pressure in the three-stage series flash evaporation is 0.2-0.4Mpa, the steam outlet pressure of the first-stage flash evaporation tank is-0.03 Mpa, the steam outlet pressure of the second-stage flash evaporation tank is-0.05 Mpa, the steam outlet pressure of the third-stage flash evaporation tank is-0.08 Mpa, and the steam temperatures of the first-stage flash evaporation and the third-stage flash evaporation are respectively 70-85 ℃, 60-75 ℃ and 55-65 ℃ in sequence.

7. The utilization method according to claim 1, wherein the bundle dryer is a corn husk bundle dryer, a corn protein bundle dryer or a corn germ bundle dryer.

8. A method for utilizing the drying waste heat of a byproduct tube bundle in the production of corn starch is characterized by adopting the utilization method of any one of claims 1 to 7.

Technical Field

The embodiment of the invention relates to the technical field of tube bundle drying, in particular to a method for utilizing waste heat in a tube bundle drying process and application thereof.

Background

The corn starch processing technology is divided into a dry method technology and a wet grinding method technology according to different properties, and the wet grinding method starch production accounts for more than 95 percent of the starch production at present due to high efficiency and stable product quality. The process features that corn is treated through soaking, crushing, embryo cyclonic separation, fiber washing separation, gluten separation, concentration and other main steps to obtain starch product over 65% and side products including corn slurry, corn embryo, corn gluten, corn dreg skin, etc.

The most common tube bundle drying equipment is used for drying the byproducts, materials enter the machine from a feed port on the side by using a feed auger, and are lifted up and pushed forward through a shoveling plate arranged at the outer edge of the tube bundle until the materials are pushed out from a feed end to a discharge port at the other end; in the process, steam enters the end socket from one section of the tube bundle and is uniformly distributed in the tube bundle, and the materials are heated and dried by the contact of the tube walls.

However, in the prior art, after steam is subjected to heat exchange, waste steam generated by drying materials at a discharge port contains dust materials and has burnt peculiar smell, and visual pollution and energy waste can be caused when the waste steam is directly discharged into the atmosphere. Meanwhile, condensed water formed after heat exchange and temperature reduction of the steam drying materials is discharged from the other end of the tube bundle, the temperature of the condensed water is about 85-95 ℃, the heat energy is not fully utilized, and energy waste is caused.

Disclosure of Invention

Therefore, the embodiment of the invention provides a method for utilizing waste heat in a tube bundle drying process, which aims to solve the problems of visual pollution and energy waste in the existing tube bundle drying process.

In order to achieve the above object, the embodiments of the present invention provide the following technical solutions:

according to a first aspect of the embodiments of the present invention, there is provided a method for utilizing waste heat in a tube bundle drying process, the method for utilizing waste heat includes recycling waste heat in waste steam and/or condensed water discharged in a tube bundle drying process, wherein:

the recycling of waste heat in the waste steam comprises:

washing waste steam discharged from a discharge port of the tube bundle dryer by a primary washing tower to remove organic and/or inorganic materials in the waste steam, washing the waste steam subjected to primary washing by a secondary alkaline washing tower to remove acid gas in the waste steam, carrying out flash evaporation on washing liquid subjected to primary washing, and heating and concentrating materials by flash evaporation steam obtained by flash evaporation and unsaturated steam subjected to secondary alkaline washing by an evaporator heating chamber;

the recycling of waste heat in the condensate water comprises:

and carrying out three-stage series flash evaporation on the condensate water discharged from the tube bundle dryer, heating and concentrating the material by flash steam obtained by the three-stage series flash evaporation through an evaporator heating chamber, and recycling the flash condensate water back to the electric boiler.

By the method, waste steam discharged from the tube bundle dryer and heat in condensed water can be fully recycled, and materials can be concentrated and heated; in addition, through tertiary series connection flash distillation can furthest's realization heat recycle, solved the direct vision pollution and the energy waste that leads to waste steam discharge that exist among the prior art to and the extravagant problem of energy in the condensate water.

Further, the recycling of waste heat in the exhaust steam further comprises:

adjusting the pH value of flash evaporation liquid obtained after flash evaporation to 6.5-8.0, then, feeding the flash evaporation liquid into an IC high-efficiency anaerobic reactor for treatment, heating methane gas generated by treatment by a hot blast stove, adjusting the pH value of treated overflow water to 7.0-8.0, then, sequentially feeding the overflow water into an aerobic treatment tank, a sedimentation tank and an aeration biological filter tank, and discharging the overflow water after reaching the standard.

Furthermore, the anaerobic bacteria in the IC high-efficiency anaerobic reactor and the aerobic bacteria in the aerobic treatment tank are all conventional strains in the field.

Through adjusting the flash distillation liquid to appropriate pH, can be better through anaerobism and aerobic treatment, organic matter in the flash distillation liquid of getting rid of that can be better for the flash distillation water reaches the standard of discharging.

Further, in the recycling of the waste heat in the waste steam, the steam inlet pressure of the primary washing tower and the steam inlet pressure of the secondary alkaline washing tower are respectively 0.2-0.4Mpa, and the temperature of the unsaturated steam after the secondary alkaline washing is 75-90 ℃.

Further, the recycling of waste heat in the exhaust steam further comprises:

and (3) carrying out flash evaporation on the alkaline washing liquid subjected to the secondary alkaline washing, obtaining flash evaporation liquid by flash evaporation and recycling the flash evaporation liquid for the secondary alkaline washing, and heating and concentrating the materials by flash evaporation steam obtained by flash evaporation through an evaporator heating chamber.

According to the invention, the volatile peculiar smell gas of the material doped in the mixed gas can be removed through alkaline washing, so that the gas after alkaline washing reaches the emission standard, and the environmental pollution is reduced; in addition, the alkali liquor can be recycled by carrying out flash evaporation on the alkali liquor, and the waste heat in the alkali liquor can be fully recycled, so that the waste heat utilization rate in waste steam is improved.

Further, in the recycling of the waste heat in the waste steam, the flash evaporation steam inlet pressure is 0.2-0.4Mpa, and the steam outlet pressure is-0.08-0.1 Mpa; the pH value of alkaline liquor used for secondary alkaline washing is 8.0-9.0.

Further, in the recycling of the waste heat in the condensed water, the steam inlet pressure in the three-stage series flash evaporation is 0.2-0.4Mpa, the steam outlet pressure of the first-stage flash evaporation tank is-0.03 Mpa, the steam outlet pressure of the second-stage flash evaporation tank is-0.05 Mpa, the steam outlet pressure of the third-stage flash evaporation tank is-0.08 Mpa, and the steam temperatures of the first-stage flash evaporation and the third-stage flash evaporation are respectively 70-85 ℃, 60-75 ℃ and 55-65 ℃ in sequence.

Further, the tube bundle dryer is a corn husk tube bundle dryer, a corn protein tube bundle dryer or a corn germ tube bundle dryer.

According to a second aspect of the embodiment of the invention, the method for utilizing the residual heat of the byproduct tube bundle drying in the corn starch production is provided, and the method for utilizing the residual heat of the byproduct tube bundle drying in the corn starch production is carried out by adopting the utilization method.

The embodiment of the invention has the following advantages:

(1) the utilization method can fully recover and utilize the heat in the waste steam and the condensed water discharged from the tube bundle dryer, and can realize the concentration and heating of the materials; in addition, can furthest's realization thermal recycle through tertiary flash distillation, solve the direct polluted environment and the energy waste that leads to waste steam emission that exist among the prior art to and the extravagant problem of energy in the condensate water.

(2) According to the invention, the volatile peculiar smell gas of the material doped in the mixed gas can be removed through alkaline washing, so that the gas after alkaline washing reaches the emission standard, and the environmental pollution is reduced; in addition, the alkali liquor can be recycled by carrying out flash evaporation on the alkali liquor, and the waste heat in the alkali liquor can be fully recycled, so that the waste heat utilization rate in waste steam is improved.

Detailed Description

The present invention is described in terms of particular embodiments, other advantages and features of the invention will become apparent to those skilled in the art from the following disclosure, and it is to be understood that the described embodiments are merely exemplary of the invention and that it is not intended to limit the invention to the particular embodiments disclosed. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.